Volcanoes of the American West: Recording and Representing Data
Objective
Big Idea
Opener
I explain to students that there a number of ways we could approach graphing data about the time frames in which volcanoes were active.
- We could round the eruption dates to the closest thousand.
- We could record tally points for each active volcano within a time period. I use these dates (1912, 1779 and 1400) as examples. On the tally chart, 1912 would fall into the category of the most recently active volcanoes in Oregon. 1779 would fall into the second category (American Revolution until the turn of the last century) and 1400 would fall into a century long time period.
- Alternately, if we round (I go through the 3 examples with the students) then both 1912 and 1779 would be rounded to 2000. Rounding really has a different context when we are viewing it as a way to convey data about time periods.
The students quickly understand that rounding to the closest thousand distorts the way in which we read the data, at least for relatively recent volcanoes.
* If you have 2 minutes extra, this is stunning footage of a volcanic eruption in Iceland in 2010. (Fimmvorduhals). Sometimes I use videos such as this during transition times, especially coming back in from recess when I want them to settle.
Active Engagement
Students transfer the data from their volcano study guide(s) to the Active Volcanoes Time Frame Chart. This is confusing for them because time is confusing, especially the concept of BC/BCE. We fill the chart together.
Then student create and label a bar graph showing the data about Eruptions in the Pacific Northwest. This is the Volcano Graph Teacher Version.
Students answer the following questions about their data table and graph:
- Which format makes the data easier to understand, for you, the table, the chart, or the volcano by volcano study page? Why?
- Write this as a fraction: How many volcanoes in (Oregon, Pacific Northwest) have been active since the turn of the last century?
- Write this as a fraction: How many volcanoes haven't been active for at least 2000 years?
- Write a one step question that could be answered using this graph. Write a two step question that could be answered using this graph. Write a related question that can't be answered by this graph, but could be answered through further research.
Wrap-up
I ask students to answer one of the following questions: (orally or in writing)
How does making a graph help you better understand the data about the time period in which volcanoes in (Oregon, the Pacific Northwest) have been most recently active?
Explain (full sentences of course) which method makes more sense to you, and why...
- rounding the closest eruption date to the nearest hundred
- rounding the closest eruption date to the nearest thousand
- determining the total number of volcanoes that have erupted in a given time period
